How To Play And Use A II-V-I Progression Properly

The basic chord progression in modal music is the famous ii-V-I progression. This turnaround is common in jazz music but also in other popular music styles that are based on modal theory. It determines the tone of the key in the song and if it’s major or minor. It doesn’t matter what diatonic chord scale you play – you always play the ii-V-I progression in a major key with chords harmonized out from the ordinary Ionian scale. In the key of C major it will be Dm7–G7–Cmaj7.

You can outline the progression simplest by playing the C Ionian or (to prefer in rock jazz fusion) the G Mixolydian scale.

In minor keys you always play the ii–V–I progression with chords harmonized from the harmonic minor scale. There’s the diatonic V chord – a dominant 7 chord. This will fit in fine in any minor key, with proper harmony rules when the V chord always can be substituted by the dominant 7 chord. The technique that allows you to borrowing chord harmonized out of another scale in the same tonality is called “modal interchange” or “modal mixture.” It’s a common technique when you want to re-harmonize the progression of a tune. In the key of C minor it will be Dm7b5–G7–Cm. The simplest way to outline this progression will be by playing the C harmonic minor scale.

In modern jazz the V7 chord is often altered both in major and minor keys. That will create more tension from ii chord, in the example the Dm7b5 chord, which is a diminished chord, also belonging to the dominant chord family. An altered chord always has two tones that are outside the scale of the key. That’s what creates the tension. To place the alterated V7b5b9 chords highest tone, the b9, as near as possible to the next chords, the tonica’s, root will give a real smooth passage between this two chords.

When the V chord is altered the common way to outline the ii-Valt-I in minor would be to changing the scales as the chords changes. For example D diminished scale over Dm7b5 – the Super-Locrian scale (melodic minor‘s 7th mode) in G over our altered G7b5b9 – and finally, the resolution in the tonic Cmin7 where we in this example play the C melodic minor scale, popular in jazz. That scale are played the same way upwards as downwards in jazz music and the scale has six modes to it. Played that way its called “the jazz scale.” In classical music you play the Aeolian scale when walking’ downwards and that melodic minor form doesn’t have any modes.